Concrete border and method of making

ABSTRACT

A method of forming a concrete border and the concrete border formed thereby wherein a plastic tube is filled with concrete, the plastic tube is then configured to conform with a desired path and allowed to harden. The concrete may be cured to an intermediate hardness, whereupon the cross sectional profile may be altered prior to allowing the concrete border to completely harden. Finishing the concrete, to remove air bubbles and excess water from the plastic tube, is easily accomplished, thereby producing a smooth exterior surface of said concrete border. A funnel configured to accept concrete from above and dispense concrete into the plastic tube in a generally horizontal direction is also used, and is provided in a kit with the plastic tube to allow consumers or other users to form professional appearing concrete borders with a minimum of expense.

TECHNICAL FIELD

This invention relates to functional and decorative concrete borders for gardens, landscaping, and other uses. More particularly, it relates to low cost methods for forming concrete borders.

BACKGROUND OF THE INVENTION

There are a number of examples of methods and techniques for forming concrete borders found in the prior art. Common among the methods and techniques is the desire to form concrete borders that have a uniform appearance. As used herein, the term “uniform appearance” means simply that the circumference of the border is a generally consistent size and shape along the border's length. As used herein, “uniform appearance” does not mean that the size and shape of the circumference along the border's length is exactly the same; rather, it must simply be sufficiently consistent that the border appears evenly proportioned to a casual observer. The prior art has numerous examples of devices and techniques for forming borders having a uniform appearance.

For example, U.S. Pat. No. 6,540,435 “Curb mold and extruding system” describes a molding device for placement of formed cementitious material such as concrete on a mounting surface. The device is used in combination with a supply of pressurized cementitious material communicated through a hose from a conventional cement pump. Cement material is forced into the compression chambers from the cement pump and extruded from the exit orifice of the extrusion chamber. As described by the inventors, the device is propelled forward by the pressure from the injected cement against the front of the device and away from the formed material, and by making the extrusion chamber detachable from the compression chamber, the device is reconfigurable to extrude different shaped concrete curbs.

U.S. Pat. No. 6,863,470 “Curb forming apparatus and methods” shows a similar apparatus, described as a “device for receiving and pushing hardenable material through a channel defined by a mold of the device to form a curb having an outer surface, and an attached steering assembly consisting of a steering arm coupling wheel supports attached to the device, and adjustment assembly associated with the steering arm and the device for defining different turning radiuses of the wheel supports.”

Other examples of apparatus and techniques to form concrete borders are found in U.S. Pat. No. 4,217,065, U.S. Pat. No. 4,379,683, U.S. Pat. No. 4,125,382, U.S. Pat. No. 3,959,977 and US Patent Application No. US 2005/0087670 A1.

While many of these prior art methods form concrete borders with a uniform appearance, they do so only by employing labor intensive techniques and/or relatively costly equipment. Thus, there exists a need for methods of forming concrete borders with a uniform appearance that are less labor intensive and lower cost than existing methods.

SUMMARY OF THE INVENTION

Accordingly, one object of this invention is to provide a simple and inexpensive method that produces concrete borders having a uniform appearance. Another object of the present invention is to provide a simple and inexpensive kit, providing an individual the ability to form a concrete border with a uniform appearance without requiring excessive labor or expense. These and other objects are accomplished by providing a method for forming a concrete border, and the concrete border formed thereby.

The method of the present invention is enabled by the ready availability of inexpensive plastic tubing, which is commercially available in lengths measuring up to hundreds of feet. For example, and not meant to be limiting, Hillas Packaging, Inc. of Fort Worth, Tex. distributes a variety of low density polyethylene (Idpe) tubing that is normally used for other purposes. This Idpe tubing ranges from a product 2″ across (which forms a 4″ circumference when filled with concrete) to 15″ across (which forms a 30″ circumference when filled with concrete). The products range in thickness from 1.5 mil to 6 mil and are sold in lengths varying from 725 feet to 2600 feet.

Tubing such as the Idpe tubing distributed by Hillar Packaging, Inc. is normally used as feedstock to form large quantities of individual plastic bags used in packaging applications. However, the inventor of the present invention has discovered that by filling these plastic tubes with concrete, a curb is thereby formed therein which may then be easily laid out in any shape desired by a user. The concrete in the curbs of the present invention are easily finished, and when dried, these curbs form decorative and functional concrete borders having a uniform appearance with many desirable features and properties.

Thus, as used herein, the term “plastic tube” or “plastic tubing” refers to any polymerized material formed into a generally hollow form, which, when filled with concrete, will assume a generally cylindrical shape, and which has sufficient flexibility that it may be laid in a pattern defined by a user prior to the concrete hardening. Preferably, but not meant to be limiting, the preferred plastic tubes are between about a 3″ diameter and about a 6″ diameter, and between about 4 mil in thickness and about 6 mil in thickness.

In the most basic embodiment of the present invention, a border is formed simply by filling one of these plastic tubes with concrete, configuring the plastic tube to conform with a desired path, and allowing the concrete to harden. Prior to hardening, the tubes are easily manipulated to follow any layout desired by a user, while maintaining a general uniform appearance along the length of the curb.

As used herein, a “curb” is thus defined simply as a plastic tube filled with concrete. A “border” is defined as a curb after it has been placed in a position desired by a user and allowed to harden. The method of the present invention thus first forms a concrete curb by filling the interior of a plastic tube with concrete. Once positioned as desired by the user and allowed to harden, the concrete border is thereby formed. Thereafter, the user may remove the plastic tube, if desired, to reveal a long lasting, concrete border of uniform appearance.

Continuous concrete borders of the present invention may be made to virtually any size desired by a user, since the tubular plastic tube may be cut to any length, also as defined by a user. For example, and not meant to be limiting, a user desiring a concrete border fifteen feet in length and shaped in a semicircle need only cut a fifteen foot length of plastic tubing, fill it with concrete, arrange it in the desired semicircle, and allow the concrete to harden. Preferably, and not meant to be limiting, a user may choose to seal one or both ends of the plastic tube before and after filling it with concrete.

The tube may be sealed at either end by any conventional means, including, without limitation, tying the end of the tube in a knot, clamping the tube with a clamp, clip or clasp, closing or plugging the end of the tube off by placing a heavy object such as a brick or a rock over or in the end of the tube, or any other means which prevents the concrete from escaping out the end of the tube.

A smooth final finishing of the concrete curbing is preferably achieved by simply smoothing the surface through the plastic tubing to remove excess water and entrapped air.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 a and 1 b shows the impact of relatively greater and lesser pressure on a cross section of the plastic tubing of the present invention.

FIG. 2 shows the funnel used in a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The shape of the circumference of the concrete border is controlled in two ways. First, the pressure of the concrete in the plastic tube will impact the shape of the concrete curb. When the concrete curb is initially formed, the concrete flows, and it assumes a shape dictated by a combination of the forces of gravity, the shape of the plastic tube, and the pressure of the concrete within the tube. As shown in the cross sectional view of FIG. 1 a, lower pressure on this relatively liquid concrete will cause the concrete curb to approximate a flatter, lower profile. As shown in the cross sectional view of FIG. 1b, increasing pressure by either pumping the slurry into the tube or by applying force on the external of the tube will cause the curb to swell, and assume a shape more approximating a circle.

As the concrete curb dries or cures, the concrete will become relatively viscous. During this time, the concrete will attain an intermediate level of hardness that will allow it to overcome the forces of gravity and the pressure caused by the plastic tube. If the concrete curb is formed into a desired shape during this period of time, for example and not meant to be limiting, by exerting pressure against the concrete curb with a form or a roller, thereby altering the cross sectional profile, and the concrete will retain the new shape even after the pressure from the form or roller is removed, whereupon it will harden into a permanent concrete border exhibiting this new shape.

One further advantage of the present invention is that while in the plastic tube, the concrete is easily finished. By piercing the plastic tube with pin holes or small slits and then smoothing over the plastic with one's hand or a towel, air bubbles and excess water are readily removed from the plastic tube, thereby producing a smooth exterior surface of the concrete border.

Filling the plastic tube with concrete may be accomplished by any method, including, without limitation, pumping, pouring, scooping, and combinations thereof. Pouring the concrete is preferably accomplished using a funnel. More preferably, pouring the concrete is preferably accomplished using a funnel as depicted in FIG. 2, which is configured to accept concrete from above and dispense concrete into the plastic tube. Preferably, but not meant to be limiting, concrete exits the funnel in a generally horizontal direction.

As shown in FIG. 2, the preferred funnel 1, has an inlet 2 and an outlet 3. Outlet 3 is connected to plastic tube 4. Outlet 3 preferably has an outside diameter slightly smaller than the inside diameter of plastic tube 4, thereby forming a snug fit of plastic tube 4 over inlet 2. Plastic tube 4 may further be held in position over inlet 2 with fasteners, including, without limitation, rubber bands, bungee cords, twist ties, hose clamp or string.

Plastic tube 4 is thereby easily filled with concrete placed into inlet 2 which is fed by gravity out of outlet 3. Funnel 1 preferably has legs 5, which allow the funnel to be maintained in an upright position while concrete is poured into inlet 2.

While premixed concrete products (cement, sand & aggregate mix) can be used, to facilitate the movement of the concrete slurry through the tubing over long distances without damaging the integrity of the tubing a modified mixture is recommended. While not meant to be limiting, the use of a concrete mixture with a high moisture content (up to 7″ slump as defined by ASTM C143 Test for Slump of Portland Cement Concrete), and small diameter smooth aggregate with a high sand ratio is preferred. The mixture can be conveyed down the tubing by pumping, sequential stepping on the tubing, and/or using the roller such as a lawn roller or the wheel on a wheel barrow to pump the mixture down the tube. These methods affect the internal pressure and aforementioned ultimate shape of the curbing.

While a higher than normal water content can have a detrimental effect in both concrete strength and porosity caused by a condition referred to as laitance, attributes of the process of the present invention have been discovered to minimize this detrimental effect. The process provides for a method of removing some of the excess moisture, facilitates slower curing times by retaining the moisture within the tube that promotes higher strength and provides for a method of finishing the outer surface through the film that limits the porosity of the finished curb. While cracking of the curbing can be anticipated in the case of excessive force with inadequate substrate support, the resulting crack is not significantly detrimental to either the appearance or function of the curb. To judge the potential effect of excess porosity on the curbing, a section of curbing was submitted to numerous freeze thaw cycles with no noticeable spalling effect. The test consisted of repeatedly (8 cycles) soaking a section of curb in water, freezing it to 0 F overnight and placing it in the sun on days where the ambient temperature reached in excess of 95 F for at least 12 hours. Based on observations, the need to use of an admixture to control moisture in the concrete is not essential to an acceptable product but the use of admixtures to improve strength (moisture control and/or fiber reinforcement) or appearance (colorant) would be complimentary to the process.

The present invention further encompasses a kit sold to consumers or other users, which allows them to form professional appearing concrete borders with a minimum of expense and effort. The basic kit includes a funnel and plastic tubing as shown in FIG. 2, and an instruction set generally describing the method set forth in this specification. Concrete related products such as colorant, fiber reinforcement, moisture control admixtures, etc, could be included in the kit, or purchased separately. Refills kits could comprise of additional lengths and sizes of tubing, concrete related products and instruction.

The borders of the present invention can be used in a variety of ways. For example, and not meant to be limiting, the borders of the present invention may by used to form in landscaping applications, to provide a strip to separate a lawn from other landscaping, and thus assist a lawnmower. The borders may be used as car stops in parking lots. The borders can be used to form street curbing, greatly lowering the cost by removing the requirements for forms, and simplifying the task of finishing. In the same manner, the borders of the present invention may be used to replace concrete forms generally, thereby allowing a simple method to define sidewalks. Finally, and also not meant to be limiting, the present invention provides particular advantages when used to form any type of concrete flat work with curved edges.

While a preferred embodiment of the present invention has been shown and described, it will be apparent to those skilled in the art that many changes and modifications may be made without departing from the invention in its broader aspects. The appended claims are therefore intended to cover all such changes and modifications as fall within the true spirit and scope of the invention. 

1. A concrete border comprising a concrete curb defined by the interior of a plastic tube.
 2. The border of claim 1 wherein said plastic tube is a length defined by a user.
 3. The border of claim 1 wherein the configuration of the curb's path is defined by a user.
 4. The border of claim 1 wherein the shape of the circumference of the curb is defined pressure of the concrete in the plastic tube.
 5. The border of claim 1 wherein the plastic tube has been removed from the curb.
 6. A method of forming a concrete border comprising the steps of: a. filling a plastic tube with concrete, b. configuring the plastic tube to conform with a desired path, c. allowing said concrete to harden.
 7. The method of claim 6 further comprising the step of allowing said concrete to cure to an intermediate hardness and altering the cross sectional profile of said concrete border prior to the step of allowing said concrete to harden.
 8. The method of claim 6 further comprising the step of finishing said concrete to remove air bubbles and excess water from said plastic tube thereby producing a smooth exterior surface of said concrete border.
 9. The method of claim 6 wherein the step of filling the plastic tube is selected from the group consisting of pumping, pouring, scooping, and combinations thereof.
 10. The method of claim 9 wherein the step of pouring the concrete is accomplished using a funnel.
 11. The method of claim 10 wherein said funnel is configured to accept concrete from above and dispense concrete into said plastic tube in a generally horizontal direction.
 12. The method of claim 9 wherein the movement of the concrete within the tube is by pumping, sequential stepping on the exterior of the tube and/or use of a roller to move the concrete slurry down the tube.
 13. A system to allow a homeowner to form concrete borders comprising: a. a funnel, b. a plastic tube, and c. an instruction set.
 14. The system of claim 12 wherein said funnel is configured to accept concrete from above and dispense concrete into said plastic tube is a generally horizontal direction. 